1. Field of the Invention
The present invention relates to a controller, and especially relates to a controller which shortens time required for teaching of a slave axis.
2. Description of the Related Art
In a case where control for making a slave axis perform a certain operation in a manner to allow the slave axis to follow a motion of a master axis is performed, a position of the slave axis corresponding to each position of the master axis is set by teaching. In this case, when an operation is actually performed after carrying out teaching of a position of the slave axis, a speed of the slave axis that follows the master axis changes in accordance with a motion pattern of the master axis. However, the speed of the slave axis is sometimes excessively increased depending on a motion pattern of the master axis. In this case, it is necessary to perform a setting operation again by carrying out teaching of the position of the slave axis again, which results in increases of a time spent for teaching. Further, the speed change of the slave axis based on the motion pattern of the master axis generates such state that the slave axis cannot perform a smooth following operation to degrade operation accuracy, as well.
As one of means for solving these problems, a technique is known in Japanese Patent Application Laid-Open No. 2014-172159 in which when teaching is carried out while operating a conveyer in a conveying speed for teaching time which is slower than a conveying speed for an actual operation time of the conveyer, the maximum conveyable speed of the conveyer when a robot performs an actual operation based on a taught trajectory of the robot is calculated so as to display the maximum conveyable speed of the conveyer on a display unit.
However, in the above-mentioned technique disclosed in Japanese Patent Application Laid-Open No. 2014-172159, speed excess of the slave axis can be grasped only based on a speed notified after teaching, so there is a problem that teaching of the slave axis has to be repeatedly carried out to find a teaching point on which speed excess does not occur.